Revert "RegAlloc: Fix verifier error after failed allocation (#119690)"

This reverts commit 34167f99668ce4d4d6a1fb88453a8d5b56d16ed5.

Different set of verifier errors appears after other regalloc failure
tests with EXPENSIVE_CHECKS.

1 files changed, 0 insertions, 36 deletions

diff --git a/llvm/lib/CodeGen/RegAllocBase.cpp b/llvm/lib/CodeGen/RegAllocBase.cpp
index 123d5cd..50addcb 100644
--- a/llvm/lib/CodeGen/RegAllocBase.cpp
+++ b/llvm/lib/CodeGen/RegAllocBase.cpp
@@ -65,7 +65,6 @@ void RegAllocBase::init(VirtRegMap &vrm, LiveIntervals &lis,
   Matrix = &mat;
   MRI->freezeReservedRegs();
   RegClassInfo.runOnMachineFunction(vrm.getMachineFunction());
-  FailedVRegs.clear();
 }
 
 // Visit all the live registers. If they are already assigned to a physical
@@ -129,7 +128,6 @@ void RegAllocBase::allocatePhysRegs() {
 
       // Keep going after reporting the error.
       VRM->assignVirt2Phys(VirtReg->reg(), AvailablePhysReg);
-      FailedVRegs.insert(VirtReg->reg());
     } else if (AvailablePhysReg)
       Matrix->assign(*VirtReg, AvailablePhysReg);
 
@@ -163,40 +161,6 @@ void RegAllocBase::postOptimization() {
   DeadRemats.clear();
 }
 
-void RegAllocBase::cleanupFailedVRegs() {
-  SmallSet<Register, 8> JunkRegs;
-
-  for (Register FailedReg : FailedVRegs) {
-    JunkRegs.insert(FailedReg);
-
-    MCRegister PhysReg = VRM->getPhys(FailedReg);
-    LiveInterval &FailedInterval = LIS->getInterval(FailedReg);
-
-    // The liveness information for the failed register and anything interfering
-    // with the physical register we arbitrarily chose is junk and needs to be
-    // deleted.
-    for (MCRegUnitIterator Units(PhysReg, TRI); Units.isValid(); ++Units) {
-      LiveIntervalUnion::Query &Q = Matrix->query(FailedInterval, *Units);
-      for (const LiveInterval *InterferingReg : Q.interferingVRegs())
-        JunkRegs.insert(InterferingReg->reg());
-    }
-  }
-
-  // TODO: Probably need to set undef on any physreg uses not associated with
-  // a virtual register.
-  for (Register JunkReg : JunkRegs) {
-    // We still should produce valid IR. Kill all the uses and reduce the live
-    // ranges so that we don't think it's possible to introduce kill flags
-    // later which will fail the verifier.
-    for (MachineOperand &MO : MRI->reg_operands(JunkReg)) {
-      if (MO.readsReg())
-        MO.setIsUndef(true);
-    }
-
-    LIS->shrinkToUses(&LIS->getInterval(JunkReg));
-  }
-}
-
 void RegAllocBase::enqueue(const LiveInterval *LI) {
   const Register Reg = LI->reg();